IR TRANSMITTER BLOK PCB ASSEMBLY INSTRUCTIONS Copyright EduTek Ltd Rev. 2
Circuit Details The circuit is shown below with a parts list of components. Check through this list and identify each component. Label R R2 R3 C C2 D D2 Q IC SW,2 Component Name 470Ω resistor KΩ resistor 22Ω resistor 47uF electrolytic capacitor uf ceramic dipped capacitor BZX44C, 5v zener diode Infra-Red LED 5mm BC337 transistor PIC6F29 PIC IC Tactile switch 6x67mm No. 2 Miscellaneous 8 pin DIL IC holder 3 way header plug Jumper 2 way PCB terminal block No. 2 Copyright EduTek Ltd
ASSEMBLY Below is the PCB with no components. The markings show the number and outline of each component. Before starting, check through the following: Ensure you have safety goggles and adequate ventilation. Use a soldering iron stand with a damp sponge to clean the iron tip regularly. Use some small Wire-cutters to remove excess wire and have some snipe-nose pliers.
Resistors There are 3 resistors, all are a different value. They must be inserted in the correct place but can be inserted either way round. Bend thelegs near to the resistor body at 90 degrees to ease fitting into thepcb. R = 470Ω, (Yellow, violet, brown, gold) R2 = KΩ, (Brown, black, red, gold) R3 = 22Ω, (Red, red, black, gold)
Zener Diode The zener diode is a small glass component. It has a black band at one end, this is the cathode (negative) connection. This connection should be in the top hole. D = BZX55C, 5v Shape the wires like the resistors, before inserting the zener diode into the PCB.
IC Holder Socket The IC holder allows easy insertion of the IC. It should be soldered with the notch on the top facing upwards. This will match up with theic later on. To stop the IC holder falling out when you are soldering it, bend over two legs in opposite corners. They are quite short so there is not much wireto bend. Take care not to stab your finger.
Capacitor non-polarised There is one non-polarised capacitor, C = uf. Because it has no polarity, it can be inserted either way round. (May also be yellow in colour) C = uf, (marked as 05 )
Transistor There is one NPN transistor, Q = BC337. The legs should already be bent to shape. It must be inserted with the flat face on the left as shown. If the legs of the transistor are close together, bend the legs outwards slightly before inserting into the PCB.
Switches There are 2 PTM click-effect switches. They should be positioned horizontally as shown below. The pads are enlarged to allow for extra solder. Try to ensure they sit level to the PCB.
Terminal Connector Blocks There is one 4-way terminal block. It is made from two 2-way connectors and fits on the left facing outwards. Slide one 2-way connector down the side of the other so the grooves fit together.
Header Plug The header plug enables different settings for the circuit. Once soldered, you can fit the jumper horizontally on either theleft two pins or the right two pins. (The jumper can be omitted completely).
Capacitors polarised There is one polarised capacitor, C, a 0uF electrolytic type. It has polarity and must be inserted with the longer wire inserted into the hole marked +. C = 47uF elec. There are 2 ways to identify the polarity of an electrolytic capacitor: The positive connection is the longest wire. The negative connection has a silver stripe above it on the casing of the capacitor.
IR LED There is one 5mm infra-red LED. It must be inserted with the longer wire in the hole with the + sign next to it. Insert it about 8-0mm above the PCB so it can be bent at 90 degrees, in line with the PCB. There are 2 ways to identify the polarity of an LED: The positive connection is the longest wire The negative connection has a flat chamfer on the rim above it.
Integrated Circuit IC Finally insert the IC with the notch facing upwards, to match the IC holder. Take care that all the pins of the IC are properly located into the holder.